不同容量平衡盐液对初进高原大鼠失血性休克合并肺水肿的复苏效果

目的 :探讨不同容量平衡盐液对初进高原大鼠失血性休克合并肺水肿的复苏效果 ,明确其液体复苏有效量及限量。方法 :初进高原 (西藏拉萨 ) SD大鼠 12 6只 ,戊巴比妥钠麻醉 ,维持血压 5 0 m m Hg( 1mm Hg=0 .133 k Pa) 1h加油酸 ( 5 0μl/ kg)静脉注射复制失血性休克合并肺水肿模型 (正常对照组不放血、不给油酸 )。第一部分实验 6 3只大鼠分为正常对照组、单纯失血性休克不复苏组、失血性休克合并肺水肿不复苏组、失血性休克合并肺水肿输注失血量 0 .5倍、1倍、1.5倍、2倍和 3倍的乳酸林格氏液 ( L R)和 1倍失血量 L R加甘露醇( 10 m l/ kg)组 ,观察液体输注后 15、30、6 0和 12 0 m in的血流动力学指标变化 ,30和 12 0 min的血气指标变化和 12 0 min肺、脑含水量变化 ,每组 7只动物。第二部分实验观察不同容量 L R输注对休克大鼠存活时间的影响。结果 :0 .5倍容量 L R输注可明显改善休克大鼠平均动脉压 ( MAP)、左心室内压 ( L VSP)和左心室内压最大变化速率 (± dp/ dt max)等血流动力学指标 ,延长存活时间 ( P均 <0 .0 1) ,不增加休克动物肺、脑含水量 ,对血气指标无明显影响 ;1倍容量 L R输注可轻度改善休克动物血流动力学指标 ,轻度延长存活时间 ,增加肺含水量 ,对血气指标无显著影响 ;1.5倍、 2倍

Effect of different volumes of fluid resuscitation on hemorrhagic shock with pulmonary edema at high altitude in the unacclimated rat

OBJECTIVE: To study the effects of different volumes of fluid resuscitation on hemorrhagic shock with pulmonary edema at high altitude in the unacclimated rat. METHODS: One hundred and twenty-six SD rats transported to Lasa, Tibet, 3 760 meters above the sea level, were anesthetized one week later with sodium pentobarbital (30 mg/kg, intraperitoneal). Hemorrhagic shock with pulmonary edema model was induced by hemorrhage (50 mm Hg for 1 hour, 1 mmHg=0.133 kPa) plus intravenous injection of oleic acid (50 microl/kg). Experiments were then conducted in two parts. Sixty-three rats in part I were equally divided into nine groups (n=7): normal control, hemorrhagic shock control, hemorrhagic shock with pulmonary edema (HSPE) without fluid infusion, HSPE plus infusing lactated Ringer's solution (LR) with 0.5-, 1-, 1.5-, 2- or 3- fold volume shed blood, and 1 volume of LR plus mannitol (10 ml/kg). Hemodynamic parameters including mean arterial blood pressure (MAP), left intraventricular systolic pressure (LVSP) and the maximal change rate of intraventricular pressure rise or decline (+/- dp/dt max) were observed at 15, 30, 60 and 120 minutes after infusion, blood gases were measured at 30 and 120 minutes after infusion and the water content of lung and brain was determined at 120 minutes after infusion. In part II, additional 63 rats were used to observe the effect of different volumes of fluid resuscitation on survival time of HSPE rats. RESULTS: 0.5 volume of LR infusion significantly improved MAP, LVSP and +/- dp/dt max, prolonged the survival time of HSPE animals (all P<0.01), while it did not increase the water content of lung and brain and had no marked influence on blood gases. One volume of LR infusion slightly improved hemodynamic parameters, prolonged the survival time and increased the water content of lung. More than 1 volume of LR infusion including 1.5-, 2- and 3- fold volume LR deteriorated the hemodynamic parameters and decreased the survival time of shocked animal, meanwhile they apparently increased the water content of lung. One volume of LR plus mannitol (10 ml/kg) infusion did not improve the hemodynamic parameters and blood gases; also it did not decrease the water content of lung. CONCLUSION: The tolerance to fluid infusion for the unacclimated animal subjected to hemorrhagic shock with pulmonary edema at high altitude is significantly decreased. 0.5-1 volume of LR infusion appears to be beneficial effect on resuscitation at high altitude, while over 1 volume of LR infusion would aggravate pulmonary edema and exacerbate fluid resuscitation effect.